Drag Estimation and Satellite Orbit Determination

摘要

Like the weather, upper atmospheric density often behaves upredictably. Even the best models of the upper atmosphere cannot consistently predict atmospheric density for Transit System satellites (1000 km) to the desired high precision. A comprehensive evaluation is presented of the drag estimation concept as a tool in routinely determining the orbit of the Transit System; the benefits to the Transit System are also examined. The resulting data (fitted along-track bias force) can be used subsequently to study upper atmospheric density variations at Transit satellite altitudes that will lead ultimately to improved upper atmospheric density models. Drag estimation in satellite orbit determination yields higher precision-tracked (determined) ephemerides and significantly improves the prediction (extrapolated satellite position) accuracy of the Transit System. (Author)